Seating state detection device

Abstract

To provide a seating state detection device which can identify a direct-seating state in which an occupant is directly seated on a seat or a state in which the occupant is seated on an auxiliary device for infant when detecting the presence / absence of an occupant in a cabin.SOLUTION: A seating state detection device comprises: an acquisition unit which acquires, for example, a detection signal group in a prescribed period which is output as a result of wave transmission / reception by a radio wave sensor mounted on a vehicle; a signal extraction unit which extracts a specific intensity signal within a prescribed reflection intensity range from the detection signal group; and a determination unit which determines a first boarding state in which an occupant of the vehicle is directly seated on a seat or a second boarding state in which the occupant is seated on an auxiliary device for infant on the basis of the distribution mode of the specific intensity signal.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present invention relates to a seating state detection device. [Background technology]

[0002] Conventionally, there have been proposed technologies that use various sensors installed in a vehicle to detect the presence or absence of occupants in the vehicle cabin, the number of occupants, distinguish between adults and children, and reflect the results in vehicle control. For example, there has been proposed a technology that uses a radio wave sensor to detect the presence or absence of occupants, and if the occupant is not fastening the seat belt while the vehicle is running, a so-called "belt reminder" is output. If the occupant is sitting upright in the seat, it is easy to detect whether the seat belt is fastened, and it is possible to appropriately output the belt reminder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-202921 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, there are cases where an occupant (child) is seated in a child support device, such as a child seat or a junior seat, attached to a vehicle seat. Methods for fastening the child support device to the seat include a belt fastening type that uses a seat belt provided on each seat to restrain the child support device, and a direct fastening type (ISOFIX type) that fastens the child support device directly to a part of the seat (for example, a metal fitting fixed to the seat) without using a seat belt. When a direct fastening type child support device is attached, a belt reminder may be output erroneously. For example, in the case of a belt fastening type child support device, the seat belt, which is a condition for outputting the belt reminder, is always fastened, so the belt reminder is not output (it is assumed that the child is fastened with the belt provided on the child support device). On the other hand, in the case of a direct fixing type child support device, the seat belt of the seat on which the child support device is placed is not used, so if an occupant (child) is detected in the child support device while the vehicle is traveling, a belt reminder is output, which may be annoying to the occupant.

[0005] Therefore, one of the objectives of the present invention is to provide a seating state detection device that, when detecting the presence or absence of an occupant in the vehicle compartment, can distinguish whether the occupant is sitting directly in the seat or in a child support device. [Means for solving the problem]

[0006] A vehicle seating state detection device according to an embodiment of the present invention includes, for example, an acquisition unit that acquires a group of detection signals for a predetermined period output as a result of transmission and reception of waves by a radio wave sensor mounted on a vehicle, a signal extraction unit that extracts a specific intensity signal within a predetermined reflection intensity range from the group of detection signals, and a determination unit that determines whether an occupant of the vehicle is in a first riding state in which the occupant sits upright in a seat or a second riding state in which the occupant is seated in a child support device based on a distribution pattern of the specific intensity signal. The signal extraction unit extracts, from the group of detection signals, a number of first detection signals included in a first reflection intensity range equal to or greater than a predetermined first intensity, and a number of second detection signals included in a second reflection intensity range including the first intensity, and the determination unit determines whether the state is the first on-board state or the second on-board state based on a magnitude of a difference between the number of the first detection signals and the number of the second detection signals.According to this configuration, for example, by focusing on a specific intensity signal, it becomes easier to efficiently obtain a detection signal when an occupant (infant) is seated in the child support device, and it becomes easier to distinguish between the first and second riding states. In addition, it becomes possible to efficiently extract a detection signal of a predetermined strength (e.g., strength weaker than a certain threshold value) when the infant support device moves due to movement (e.g., breathing) of an occupant (infant) seated in the infant support device, thereby improving the accuracy of judgment by the judgment unit.

[0008] Books Vehicle seating state detection device according to an embodiment of the present invention Place ,for example, The vehicle seat includes an acquisition unit that acquires a group of detection signals for a predetermined period output as a result of transmission and reception of waves by a radio wave sensor mounted on the vehicle, a signal extraction unit that extracts a specific intensity signal within a predetermined reflection intensity range from the group of detection signals, and a determination unit that determines whether an occupant of the vehicle is in a first riding state in which the occupant sits upright in a seat or a second riding state in which the occupant sits in a child support device based on a distribution pattern of the specific intensity signal. The determination unit determines whether the vehicle is in the first riding state or the second riding state based on a distribution position of the number of the specific strength signals. do. According to this configuration, For example, by focusing on the specific strength signal, it becomes easier to efficiently obtain a detection signal when an occupant (infant) is seated in the child support device, and it becomes easier to distinguish between the first riding state and the second riding state. For example, it becomes possible for the determination section to perform determination more clearly, and the determination accuracy can be improved.

[0009] The signal extraction unit of the seating state detection device according to the embodiment of the present invention may acquire the detection signals when the detection waves of the radio wave sensor are transmitted to a position corresponding to the chest of the occupant when seated. With this configuration, it is possible to easily and accurately determine whether or not an occupant is present based on breathing movements that can be stably detected even when the occupant is sleeping, for example. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an exemplary schematic explanatory diagram showing the configuration of a vehicle equipped with a seating state detection device according to an embodiment. [Diagram 2] FIG. 2 is an exemplary schematic block diagram illustrating a configuration of the seating state detection device according to the embodiment. [Diagram 3] FIG. 3 is an exemplary graph showing the relationship between the distance and the number of plots of the detection signal from the radio wave sensor in a predetermined detection intensity range, which is detected when an occupant is seated in the child support device in the seating state detection device according to the embodiment. [Figure 4]FIG. 4 is an exemplary graph showing the relationship between the distance and the number of plots of the detection signal from the radio wave sensor in a predetermined detection intensity range, which is detected when an occupant sits upright in the seat in the seating state detection device according to the embodiment. [Diagram 5] FIG. 5 is an exemplary histogram of the number of plots of detection signals detected when an occupant sits upright in a seat and when an occupant sits in a child support device in accordance with an embodiment, when the detection intensity range is narrowed. [Figure 6] FIG. 6 is an exemplary flowchart illustrating a determination process of determining whether or not the child support device is in a seated state by the seating state detection device according to the embodiment, and a belt reminder process using the result of the determination process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Exemplary embodiments of the present invention are disclosed below. The configurations of the embodiments described below, as well as the actions, results, and effects brought about by the configurations, are merely examples. The present invention can be realized with configurations other than those disclosed in the following embodiments, and it is possible to obtain at least one of various effects based on the basic configuration and derivative effects.

[0012] The seating state detection device of this embodiment transmits, for example, radio waves of a predetermined frequency transmitted from a radio wave sensor to a seat present in the vehicle cabin, a child support device (e.g., a child seat, a junior seat, etc.) fixed to the seat, and an occupant (adult, child, infant, etc.) seated thereon, and obtains a detection signal that is a reflected wave. Based on the detection signal, the seating state detection device determines whether the vehicle occupant is in a first riding state in which the occupant sits upright in the seat, or in a second riding state in which the occupant sits in the child support device. The result of the determination by the seating state detection device is used for various vehicle controls. For example, if an occupant does not wear a seat belt while the vehicle is running, a belt reminder is output and used to call the occupant's attention. The seating state detection device will be described in detail below.

[0013] FIG. 1 is an explanatory diagram illustrating an example and schematic configuration of a vehicle 10 on which a seating state detection device according to the present embodiment is mounted.

[0014] Vehicle 10 may be, for example, an automobile (internal combustion engine automobile) using an internal combustion engine (engine, not shown) as a drive source, an automobile (electric automobile, fuel cell automobile, etc.) using an electric motor (motor, not shown) as a drive source, or an automobile using both of them as drive sources (hybrid automobile). Vehicle 10 may be equipped with various transmissions, and may be equipped with various devices (systems, parts, etc.) required to drive the internal combustion engine or electric motor.

[0015] As shown in Fig. 1, a vehicle 10 is provided with seats 12 in which passengers can be seated within a vehicle compartment 10a. In the case of vehicle 10, seats 12 are arranged in three rows, including a front row seat 12a, a middle row seat 12b, and a rear row seat 12c. In the case of Fig. 1, a child support device 14 (such as a child seat or a junior seat) that is used when a child boards vehicle 10 is attached to rear row seat 12c.

[0016] In FIG. 1, the child support device 14 is a direct fixing type (ISOFIX type) in which the child support device 14 is fixed to the rear seat 12c by inserting a socket 14a provided at a corresponding position of the child support device 14 into a dedicated adapter 12c1 (metal fitting, etc.) provided on the seat frame of the seat 12 (rear seat 12c). The adapter 12c1 is provided, for example, at a connection between the seat surface and the back of the seat 12. The direct fixing type child support device 14 has the advantages of being easier to fix, having no variation in the fixed state, and being easy to use, compared to a belt fixing type in which the child support device is restrained using a seat belt provided on the seat 12. Note that it is possible to provide an adapter similar to the adapter 12c1 to each seat 12, and the direct fixing type child support device 14 may be attached and detached to any seat 12.

[0017] Each seat 12 is provided with a seat belt 16 for fastening a seated occupant. A metal part of the seat belt 16 is inserted into a seat belt adapter 18 provided on each seat 12, and the seat belt 16 is fastened to the seat 12 to fasten the occupant. An occupant T1 (driver: adult) seated on the front row seat 12a is fastened by inserting a seat belt 16a into the seat belt adapter 18, and an occupant T2 (e.g., a child) seated on the middle row seat 12b is fastened by inserting a seat belt 16b into the seat belt adapter 18. The child support device 14 fastened to the rear row seat 12c is provided with a dedicated seat belt (e.g., a four-point type) (not shown) that can fasten an occupant T3 (a child) to be seated. Although not shown, the rear row seat 12c is also provided with a seat belt and a seat belt adapter similar to the seat belt 16b attached to the middle row seat 12b. Therefore, when the child restraint device 14 is not installed on the rear seat 12c, the occupant (adult or child) can be safely secured in place using the seat belt.

[0018] As described above, in the case of the direct fastening type child support apparatus 14, since the seat belt provided in the seat belt 16 is not used, even if the child support apparatus 14 is attached to the rear seat 12c and the occupant T3 seated in the child support apparatus 14 is wearing a dedicated seat belt, the seat belt of the rear seat 12c is not used and a belt reminder is output during driving. That is, in order to execute accurate vehicle control such as a belt reminder in the vehicle 10 equipped with the direct fastening type child support apparatus 14, the seating state detection device mounted on the vehicle 10 needs to determine whether the occupant of the vehicle 10 is in the first riding state where the occupant sits upright in the seat 12 or the second riding state where the occupant sits in the child support apparatus 14.

[0019] Therefore, in the case of the vehicle 10 equipped with the directly fixed type child support device 14, the radio wave sensor 20 is provided to output a detection signal used to determine whether the vehicle is in the first riding state or the second riding state in which the child is seated on the child support device 14. A well-known sensor can be used as the radio wave sensor 20. The radio wave sensor 20 may be installed at any position in the vehicle interior 10a as long as it can transmit radio waves (microwaves, millimeter waves, etc.) to the seat 12 and the child support device 14, which are the detection targets, and to the passenger seated thereon, and can receive reflected waves (detection signals) of the transmitted transmission waves. In the case of FIG. 1, the child support device 14 can be installed on at least one of the middle row seat 12b and the rear row seat 12c. Therefore, the radio wave sensor 20 is installed at a position where radio waves can be transmitted and received even when the child support device 14 is installed on the rear row seat 12c, the middle row seat 12b, or neither of them. For example, the radio wave sensor 20 is disposed at a position on the ceiling surface of the vehicle interior 10a, approximately in the center in the vehicle width direction, between the middle row seat 12b and the rear row seat 12c in the vehicle front-rear direction (for example, a position slightly behind the headrest of the middle row seat 12b). In the example of Fig. 1, the detection area E of the radio wave sensor 20 disposed on the ceiling surface covers the middle row seat 12b and the rear row seat 12c.

[0020] The detection signals (group) acquired from the radio wave sensor 20 are sequentially provided to the seating state detection device 22, which judges the seating state. The judgment result or the control result based on the judgment result is output from the notification device 24 (for example, an audio output device 24a (speaker), a display device, etc.) and notified to the occupant.

[0021] FIG. 2 is an exemplary schematic block diagram showing the configuration of the seating state detection device 22. As shown in FIG.

[0022] The seating state detection device 22 includes an acquisition unit 22a, a signal extraction unit 22b, a determination unit 22c, a notification unit 22d, and the like.

[0023] The acquisition unit 22a sequentially acquires a group of detection signals for a predetermined period output as a result of transmission and reception of waves by the radio wave sensor 20. When the acquisition unit 22a realizes the belt reminder function based on the detection result of the seating state detection device 22, for example, when it is confirmed that the vehicle 10 is moving based on the vehicle speed information provided by the vehicle 10, the acquisition unit 22a issues an operation request to the radio wave sensor 20 to transmit radio waves of a predetermined frequency. The radio wave sensor 20 receives reflected waves reflected by the seat 12, the child support device 14, the passenger, etc., and sequentially provides the reflected waves to the acquisition unit 22a. The acquisition unit 22a sequentially provides the acquired group of detection signals to the signal extraction unit 22b.

[0024] The signal extraction unit 22b extracts a specific intensity signal within a predetermined reflection intensity range from the group of detection signals provided by the acquisition unit 22a. The radio wave sensor 20 can detect an object whose distance from the sensor changes (amount of movement). The greater the amount of movement of the object, the greater the intensity of the detection signal (reflected radio wave). That is, the radio wave sensor 20 can measure the received signal at each position in a three-dimensional space, and determines that there is "movement" when the absolute value of the time difference of the received signal is equal to or greater than a predetermined threshold, and determines that there is no "movement" when it is less than the predetermined threshold. Each position in the three-dimensional space is a discretized value, and the total number of points where there is "movement" (the absolute value of the time difference of the received signal is equal to or greater than a predetermined threshold) in a predetermined space can be defined as the "amount of movement". In addition, the radio wave sensor 20 can detect the distance to the object that reflected the radio wave based on the time from transmission to reception of the wave. Therefore, the position where an object or moving object is detected by the group of detection signals provided by the acquisition unit 22a can be displayed as a plot having information on the reflection intensity (magnitude of movement) and position on a three-dimensional coordinate system.

[0025] Therefore, the signal extraction unit 22b can classify the detection signals by, for example, extracting specific intensity signals within a predetermined reflection intensity range from the acquired group of detection signals, and analyze the characteristics of the group of detection signals, i.e., detect the presence or absence of an object that reflected the radio waves (in this embodiment, the seat 12, the child support device 14, and an occupant who may be seated therein).

[0026] Meanwhile, body movements (movement of limbs and breathing) of occupant T3 (infant) seated in the infant support apparatus 14 and secured by a dedicated seat belt are transmitted to the infant support apparatus 14, and the infant support apparatus 14 itself also moves slightly. In this case, the small movements of the infant support apparatus 14 are also detected by the radio wave sensor 20. As described above, by extracting a specific intensity signal within a predetermined reflection intensity range from the group of detection signals provided by the seat 12, a plot of the specific intensity (intensity weaker than a predetermined threshold value) including the small movements of the infant support apparatus 14 can be displayed on a three-dimensional coordinate system.

[0027] On the other hand, for example, when an occupant T2 (e.g., a child) is sitting upright in the middle row seat 12b, the group of detection signals does not include any plots resulting from body movements transmitted to the child support device 14. Therefore, by referring to the number of plots having a detection signal (specific intensity signal) from the child support device 14, it is possible to determine whether an occupant T3 (a child) is seated in the child support device 14 or an occupant T2 (e.g., a child) is sitting upright in the seat 12.

[0028] 3 and 4, a difference occurs in the detection signals when a child is seated in the child restraint apparatus 14 and when an occupant is sitting upright in the seat 12. FIG.

[0029] Graph 26 shown as an example in FIG. 3 indicates the relationship between the distance of plots of detection signals from a radio wave sensor within a predetermined detection intensity range detected in seating state detection device 22 when an occupant (infant) is seated in child support device 14 and the number of plots.

[0030] In FIG. 3, the vertical axis indicates the distance in the Z direction (vertical direction) from the radio wave sensor 20 arranged on the ceiling surface, and the horizontal axis indicates the number of plots. The open bar M1 indicates the number of first detection signals included in the detection signal group that are included in a first reflection intensity range equal to or greater than a predetermined first intensity. The hatched bar M2 indicates the number of second detection signals included in a second reflection intensity range that includes the first intensity. In general, an infant seated in the infant support device 14 moves his / her arms, legs, and head irregularly. As a result, the number of first detection signals indicating strong movements increases. As described above, when an occupant T3 (infant) is seated in the infant support device 14, the movement of the occupant T3 is propagated to the infant support device 14, and the infant support device 14 moves (vibrates), and the intensity signals (signals of a specific intensity) weaker than a predetermined threshold value increase. In particular, since the infant support device 14 is seated in a state of close contact so as to envelop the infant, the vibration of the infant support device 14 covers a wide range. As a result, as the number of first detection signals indicating strong motion increases, the number of detection signals having an intensity lower than the predetermined threshold also increases, i.e., the number of second detection signals included in the second reflection intensity range including the first intensity increases, resulting in a characteristic distribution pattern.

[0031] Graph 28 shown as an example in FIG. 4 indicates the relationship between the distance of plots of detection signals from a radio wave sensor in a predetermined detection intensity range detected in the seating state detection device 22 when an occupant (e.g., a child) sits upright in the seat 12 and the number of plots.

[0032] In FIG. 4, the vertical axis indicates the distance in the Z direction (vertical direction) from the radio wave sensor 20 arranged on the ceiling surface, and the horizontal axis indicates the number of plots. The open bar N1 indicates the number of first detection signals included in the detection signal group that are included in a first reflection intensity range that is equal to or greater than a predetermined first intensity. The hatched bar N2 indicates the number of second detection signals included in a second reflection intensity range that includes the first intensity. In general, irregular movements of the limbs are reduced in grown children compared to infants. As a result, the open bar N1 indicating the number of first detection signals that indicate strong movements is reduced compared to the bar M1 in FIG. 3 that indicates the case of an infant. In addition, the seat 12 on which the occupant T2 sits upright is harder than the infant support device 14, and movement (vibration) is less likely to propagate. As a result, the number of detection signals that are weaker than a predetermined threshold decreases with the decrease in the number of first detection signals that indicate strong movements and the decrease in propagation to the seat 12. In other words, the number of second detection signals that are included in a second reflection intensity range that includes the first intensity also decreases, and a characteristic distribution pattern is shown. In Figures 3 and 4, detection signals with a strength weaker than the predetermined threshold include detection signals caused by vibration of the vehicle 10, but when the child support device 14 is installed with a child seated on it, the detection signals with a strength weaker than the predetermined threshold become much more numerous than when the occupant is sitting upright in the seat 12.

[0033] The determination unit 22c determines whether the passenger's on-board state is the first on-board state or the second on-board state based on the specific strength signal extracted by the signal extraction unit 22b.

[0034] For example, when comparing the bar M1 (the number of first detection signals) and the bar M2 (the number of second detection signals) indicating the specific intensity signals acquired through the radio wave sensor 20 for the passenger T3 (infant) seated in the infant support device 14 shown in FIG. 3, there is a clear difference between the bar M1 and the bar M2. Here, the difference between the bar M1 (the number of first detection signals) and the bar M2 (the number of second detection signals) corresponds to the number of detection signals whose intensity is weaker than a predetermined threshold value mainly originating from the movement of the infant support device 14 described above. In other words, when the number of detection signals (difference) originating from the movement of the infant support device 14 becomes equal to or greater than a predetermined judgment threshold value, the radio wave sensor 20 can be considered to have acquired the received signal group in a state in which the passenger T3 (infant) is seated in the infant support device 14. In other words, the judgment unit 22c can judge that the second boarding state, that is, the state in which the passenger T3 (infant) is seated in the infant support device 14, is the state based on the magnitude of the difference between the number of the first detection signals (bar M1) and the number of the second detection signals (bar M2).

[0035] On the other hand, the specific intensity signal acquired through the radio wave sensor 20 for the occupant T2 (e.g., a child) sitting upright in the seat 12 shown in FIG. 4 does not include a detection signal with an intensity weaker than a predetermined threshold value originating from the child support device 14. That is, the difference between the bar N1 (the number of first detection signals) and the bar N2 (the number of second detection signals) shown in FIG. 4 is smaller than the difference between the bar M1 and the bar M2 when the occupant T3 (a child) is seated in the child support device 14 shown in FIG. 3. Therefore, when the difference between the number of the first detection signals and the number of the second detection signals is less than the above-mentioned determination threshold, the radio wave sensor 20 can be considered to have acquired the received signal group in a state in which the occupant T2 (e.g., a child) is sitting upright in the seat 12. That is, the determination unit 22c can determine that the first boarding state, that is, the state in which the occupant T2 (e.g., a child) is sitting upright in the seat 12, based on the magnitude of the difference between the number of the first detection signals (bar M1) and the number of the second detection signals (bar M2).

[0036] As shown in FIG. 3, when an occupant T3 (infant) is seated in the infant support device 14, a group of detection signals generally indicating movement is detected from the upper end to the lower end of the seat 12 including the infant support device 14, and a difference between the bars M1 and M2 can be detected. Similarly, in FIG. 4, when an occupant T2 (e.g., a child) is sitting upright in the seat 12, a group of detection signals generally indicating movement is detected from the upper end to the lower end of the seat 12, and a difference between N1 and N2 can be detected. When an occupant T2 (e.g., a child) or an occupant T3 (infant) is seated in the vehicle 10, the occupant may be awake or asleep, and the detection signal group is likely to vary. Therefore, here, the signal extraction unit 22b acquires (focuses on) a group of detection signals when the detection wave of the radio wave sensor 20 is transmitted to a position corresponding to the chest when the occupant T2 (e.g., a child) or an occupant T3 (infant) is seated. The position equivalent to the chest is, for example, a position at -0.5 m in the Z direction with respect to the ceiling surface of the vehicle 10 on which the radio wave sensor 20 is installed. In this case, when the occupant T2 is fastened to the seat belt 16b of the middle row seat 12b, or when the occupant T3 is fastened to the linear seat belt of the child support device 14, large movements are restricted and movements associated with breathing can be stably detected. For example, the determination by the determination unit 22c can be stably performed in the area P1 in FIG. 3 or the area P2 in FIG. 4.

[0037] The histogram 30 shown as an example in FIG. 5 represents the number of plots of detection signals detected by the seating state detection device 22 when the detection intensity range is narrowed to a predetermined range in the cases where occupant T2 is sitting upright in the seat 12 and where occupant T3 is seated in the child support device 14.

[0038] FIG. 5 shows a histogram of detection signals extracted by the signal extracting unit 22b from a group of detection signals detected over a longer period than in the cases of FIG. 3 and FIG. 4, and the detection signals are plotted in a histogram. In this case, the first distribution area 30a, which is distributed in an area where the number of plots is relatively small, and the second distribution area 30b, which is distributed in an area where the number of plots is relatively large, are clearly separated. As described above, when the occupant T2 sits upright in the seat 12, the number of plots of detection signals whose intensity is weaker than the predetermined threshold from the child support device 14 is reduced because no detection signals whose intensity is weaker than the predetermined threshold from the child support device 14 are included. That is, when the distribution position of the number of plots indicates the first distribution area 30a, the determining unit 22c can determine that the seat 12 is in the first riding state in which the occupant T2 sits upright. On the other hand, when the occupant T3 sits in the child support device 14, many detection signals whose intensity is weaker than the predetermined threshold from the child support device 14 are included, and the number of plots of detection signals whose intensity is weaker than the predetermined threshold increases. That is, when the distribution position of the plot numbers indicates the second distribution region 30b, the determining unit 22c can determine that the child support apparatus 14 is in the second riding state in which the occupant T3 is seated.

[0039] In this way, when making a determination based on the distribution position of the plot numbers of detection signals when the detection intensity range is narrowed, the features indicating the first boarding state and the features indicating the second boarding state become clearer than in the cases of Figures 3 and 4. As a result, the determination unit 22c can make a more accurate determination of the boarding state.

[0040] The notification unit 22d issues a notification to the occupant based on the determination result of the determination unit 22c and information acquired from another control system of the vehicle 10. For example, a belt reminder is executed as an example of the notification. For example, when the notification unit 22d acquires information indicating that the seat belt 16b is not inserted into the seat belt adapter 18 while the vehicle 10 is running, even though it is confirmed that the occupant T2 is sitting upright in the middle row seat 12b (in the first seating state), the notification unit 22d determines that the seat belt 16b is not fastened. In this case, the determination unit 22c outputs a voice message such as "Please fasten your seat belt" via the voice output device 24a as a message to encourage the occupant T2 to fasten the seat belt 16b via the notification device 24, or displays a message to encourage the occupant T2 to fasten the seat belt on a display device at the driver's seat or a display device visible when seated in the middle row seat 12b, or lights up an indicator light. Of course, in the case where the first occupancy state is not confirmed in the middle row seat 12b (the occupant T2 is not confirmed), the belt reminder is not executed even if the seat belt 16b is not inserted into the seat belt adapter 18 while the vehicle 10 is traveling. Note that, when the belt reminder is executed, the traveling of the vehicle 10 may be restricted until it is confirmed that the seat belt 16 is fastened.

[0041] On the other hand, when the notification unit 22d confirms that the occupant T3 is seated in the child support device 14 in the rear seat 12c (second boarding state), the direct-fixing type child support device 14 is fixed to the rear seat 12c without using the seat belt of the rear seat 12c. At this time, it is assumed that the occupant T3 is fixed by the dedicated seat belt of the child support device 14. Therefore, even if the notification unit 22d acquires information indicating that the seat belt of the rear seat 12c is not inserted into the seat belt adapter while the vehicle 10 is traveling, it does not determine that the seat belt is not fastened. As a result, it is possible to avoid a malfunction in which the belt reminder is executed when the occupant T3 (child) is fixed to the child support device 14 by the dedicated seat belt.

[0042] 6 is an exemplary flowchart illustrating a process of determining whether the child support device 14 is in a seated state by the seating state detection device 22 according to the embodiment, and a belt reminder process using the result of the determination process. Note that the flowchart in FIG. 6 is an example of a process of determining the riding state based on the distribution pattern (distribution position) of the number of plots shown in FIG.

[0043] When the ignition switch of the vehicle 10 is ON, the seating state detection device 22 constantly checks whether the vehicle 10 is running (S100). When the vehicle 10 is not running (No in S100), this flow is temporarily ended.

[0044] In the process of S100, if it is confirmed that the vehicle 10 is traveling (Yes in S100), the acquisition unit 22a acquires a group of detection signals from the radio wave sensor 20 (S102). Next, the signal extraction unit 22b cuts out an RIO (region of interest) at a position corresponding to the chest from the group of detection signals (S104), and executes counting of the number of plots of detection signals when narrowed down to a detection strength range weaker than a predetermined threshold (S106). Then, the determination unit 22c executes a process of determining whether the distribution position of the number of plots indicates the first distribution region 30a or the second distribution region 30b, as described in FIG. 5 (S108).

[0045] As a result of the judgment by the judgment unit 22c, when the second boarding state (a state in which an occupant T3 (infant) is seated in the child support device 14) is not detected (No in S110), that is, when the first boarding state (an occupant T2 (e.g., a child) is sitting upright in the seat 12) is detected. In this case, the notification unit 22d checks the fastening state of the seat belt 16 of the target seat 12 (S112), and when the seat belt 16 is fastened (Yes in S112), the notification unit 22d temporarily ends this flow without executing the belt reminder.

[0046] In the process of S112, if it is not confirmed that the seat belt 16 is fastened (No in S112), a belt reminder is executed, a warning that the seat belt 16 is not fastened is given to the occupant, and this flow is temporarily ended.

[0047] In the process of S110, when the second boarding state is detected (Yes in S110), that is, it is determined that the child support device 14 of the direct fixing type is attached to the rear row seat 12c, and the occupant T3 (child) is fixed to the child support device 14 by a dedicated seat belt. As a result, this flow is temporarily ended without checking whether the seat belt 16 is fastened.

[0048] In this manner, the seating state detection device 22 of the present embodiment can easily and accurately detect whether the occupant is directly seated on the seat or in the child support device when detecting the presence or absence of an occupant in the vehicle cabin. Then, using the result of the detection, the vehicle 10 can be controlled more accurately (e.g., the seat belt reminder, etc.).

[0049] In the above embodiment, an example in which one radio wave sensor 20 is provided on the ceiling of the vehicle 10 has been shown. In another embodiment, a plurality of radio wave sensors 20 may be provided. For example, one may be provided for each row of seats 12, or one may be provided for each seat 12. For example, when the middle row seats 12b and the rear row seats 12c have three seats in the vehicle width direction, three radio wave sensors 20 may be provided in the vehicle width direction. By providing a plurality of radio wave sensors 20, more accurate determination can be made by the determination unit 22c. In addition, the installation position of the radio wave sensor 20 may be other than the ceiling, for example, the position of the headrest of the seat 12 in front of the seat 12 to be detected, or the position in the width direction (corner) other than the center in the vehicle width direction.

[0050] In addition, in the above embodiment, an example was shown in which the child support device 14 was attached to the rear seat 12c, but it can also be attached to other seats such as the middle seat 12b, and the same effects as in this embodiment can be obtained.

[0051] In addition, in this embodiment, an example is shown in which the occupant sitting upright in the seat 12 is a child, and the seating height is approximately the same as that of an occupant (child) seated in the child support device 14; however, this embodiment can also be applied to cases in which an occupant with a higher seating height (e.g., an adult) sits upright in the seat 12, and similar effects can be obtained.

[0052] In the above embodiment, an example is shown in which the seat belt reminder is executed based on the determination result of the determination unit 22c, but the determination result may be used for other functions. For example, when a small child is on board, gentler driving is desirable, so the determination result may be reflected in the acceleration / deceleration control of the vehicle 10. In addition, an example is shown in which the notification unit 22d executes the seat belt reminder, but a configuration for executing the seat belt reminder may be provided separately from the seating state detection device 22 and function based on the determination result of the seating state detection device 22.

[0053] Although the embodiments and modifications of the present invention have been described, these embodiments and modifications are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0054] 10...vehicle, 12...seat, 12a...front row seat, 12b...middle row seat, 12c...rear row seat, 14...child support device, 16, 16a, 16b...seat belt, 18...seat belt adapter, 20...radio wave sensor, 22...seating state detection device, 22a...acquisition unit, 22b...signal extraction unit, 22c...determination unit, 22d...alarm unit, 24...alarm device, 24a...audio output device.

Claims

1. an acquisition unit that acquires a group of detection signals for a predetermined period output as a result of transmission and reception of waves by a radio wave sensor mounted on a vehicle; a signal extracting unit that extracts a specific intensity signal within a predetermined reflection intensity range from the group of detection signals; a determination unit that determines whether an occupant of the vehicle is in a first riding state in which the occupant sits upright in a seat or in a second riding state in which the occupant sits in a child support device based on a distribution pattern of the specific intensity signal; Equipped with the signal extraction unit extracts, from the group of detection signals, a number of first detection signals that are included in a first reflection intensity range that is equal to or greater than a predetermined first intensity, and a number of second detection signals that are included in a second reflection intensity range that includes the first intensity; the determination unit determines whether the vehicle is in the first boarding state or the second boarding state based on a magnitude of a difference between the number of the first detection signals and the number of the second detection signals. Seating status detection device.

2. An acquisition unit that acquires a group of detection signals for a predetermined period output as a result of transmission and reception of waves by a radio wave sensor mounted on a vehicle; a signal extracting unit that extracts a specific intensity signal within a predetermined reflection intensity range from the group of detection signals; a determination unit that determines whether an occupant of the vehicle is in a first riding state in which the occupant sits upright in a seat or in a second riding state in which the occupant sits in a child support device based on a distribution pattern of the specific intensity signal; Equipped with the determination unit determines whether the vehicle is in the first on-board state or the second on-board state based on a distribution position of the number of the specific strength signals. Seating status detection device.

3. 3. The seating state detection device according to claim 1, wherein the signal extraction unit acquires the group of detection signals when detection waves from the radio wave sensor are transmitted to a position corresponding to a chest of the occupant when seated.

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