JP2012035695A - Device for detection of vehicle occupant's sitting state - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sitting state detection device that detects sitting of an occupant with a normal attitude on a seat of a vehicle without using a light source and a camera for imaging the occupant.SOLUTION: The sitting state detection device includes: four antenna elements 12-15 prepared in a door 9 beside the seat 2; and the antenna element 11 arranged above the seat 2. The antenna elements 11-15 are for receiving thermal noise of millimeter wave band radiated by the occupant, set with a sharp directional characteristic to receive agitation noise radiated from the occupant parts corresponding to arrangement positions of respective elements 11-15 (breast, waist, leg, etc.). Determination of sitting attitude is performed in such a procedure as determining whether the occupant sits on the seat 2 based on detection signals (a reception level of thermal noise of millimeter wave band) from the antenna element 11, and if the occupant sits on the seat 2, determines whether occupant's sitting attitude is normal, based on the detection signals from the antenna elements 12-15.

Description

  The present invention relates to a vehicle occupant seating state detection device that detects that an occupant is seated in a normal posture on a vehicle seat.

  The airbag provided in front of or on the side of the vehicle seat is for protecting the occupant in the event of a vehicle collision, etc., but if the occupant's posture is poor, the airbag The occupant sometimes injured the occupant.

  Therefore, conventionally, an occupant seated in a seat is imaged by a camera provided in the passenger compartment, and the occupant's sitting posture is recognized from the captured image, and the occupant is seated in a normal posture that can safely start the airbag. It has been proposed to allow the operation of the airbag only when the vehicle is in the air (see, for example, Patent Documents 1 and 2).

JP 2001-213268 A JP 2007-198929 A

  The above-described conventional apparatus captures an occupant seated in a vehicle seat with an optical camera (specifically, a CCD camera, an infrared camera, etc.), and performs image processing on the captured two-dimensional image. Since it is determined whether or not the occupant is seated in the seat in a normal posture, there is a problem that the determination (image processing) takes time.

  Further, when an occupant is imaged, it is necessary to irradiate the vicinity of the seat with light that can be imaged (natural light, infrared light, etc.), and there is a problem that a light source for that purpose and a control device that turns on the light source are necessary.

  The present invention has been made in view of these problems, and does not use a light source that irradiates the vicinity of the vehicle seat, and does not perform image processing on the captured two-dimensional image, and the occupant is in a normal posture on the vehicle seat. An object of the present invention is to provide a seating state detection device for a vehicle occupant capable of detecting that the vehicle is seated.

The invention according to claim 1, which has been made to achieve the object,
A vehicle occupant seating state detection device for detecting that an occupant is seated in a normal posture on a vehicle seat,
An occupant seated in the seated part of the seat and the upper body of the occupant who has been incorporated into the body part around the seat to be detected and is seated in a normal posture in the seat and drowned in the backrest of the seat A plurality of antenna elements each receiving thermal noise incident from a plurality of reception target positions, where the lower body is located;
A seating posture determination means for determining whether or not an occupant is seated in a normal posture on the seat from the reception level of thermal noise by the plurality of antenna elements;
It is provided with.

According to a second aspect of the present invention, there is provided the vehicle occupant seating state detecting device according to the first aspect,
One of the plurality of antenna elements is an occupant detection antenna element disposed below or above a seat to be detected,
The seating posture determination means determines whether or not an occupant is seated in a seat to be detected from a reception level of thermal noise by the occupant detection antenna element, and the occupant is seated in the seat When it is determined, it is characterized in that it is determined whether or not the occupant is seated in a normal posture from the reception level of the thermal noise from the other antenna elements.

In the seating state detection apparatus according to the first aspect, a plurality of antenna elements for receiving thermal noise are provided in place of the camera that captures the periphery of the seat to be detected.
The plurality of antenna elements are incorporated in a body part around the seat to be detected (more specifically, a door or a pillar of an automobile), and an occupant is seated in a normal posture on the seat to be detected. Sometimes, it is configured to receive thermal noise radiated from a plurality of reception target positions where the upper body of the occupant who is drowning in the back portion of the seat and the lower body of the occupant seated in the seating portion of the seat are located. .

  In other words, since thermal noise generated from a human body having temperature is stronger than thermal noise of an object, in the present invention, a plurality of antenna elements that can receive the thermal noise are seated on a seat in a normal posture. It is arranged at a position where thermal noise radiated from an arbitrary position of the upper and lower body is incident.

  In the present invention, the seating posture determination means determines whether or not the occupant is seated in a normal posture from the reception level of the thermal noise by the plurality of antenna elements arranged as described above.

  For this reason, according to the seating state detection device of the present invention, a normal posture of the vehicle seat can be obtained without using a light source that irradiates the vicinity of the vehicle seat and without performing image processing on a two-dimensional image captured by the camera. It is possible to detect that an occupant is seated.

  Therefore, according to the present invention, the time required to detect that the vehicle occupant is seated in a normal posture is shortened, and the seating state of the occupant is promptly notified to the vehicle control device such as an airbag. Can do.

  By the way, when a plurality of antenna elements are provided in a body part next to a seat such as an automobile door, or in a body part located obliquely in front of a seat such as an automobile pillar, the antenna element is A seating posture determination means for receiving thermal noise radiated from an occupant seated in a seat arranged beside the seat to be detected or from an occupant seated in a seat disposed behind the seat to be detected; However, it is conceivable that from the reception level, it is erroneously determined that the occupant is seated in a normal posture in the seat to be detected.

  Therefore, in order to prevent such a problem, as described in claim 2, an antenna for detecting an occupant is provided by disposing one of a plurality of antenna elements below or above a seat to be detected. It is used as an element, and the sitting posture determination means determines whether or not an occupant is seated in the seat to be detected from the reception level of the thermal noise by the antenna element for detecting the occupant, and the occupant is seated in the seat. If it is determined that the occupant is seated, it may be determined whether or not the occupant is seated in a normal posture based on the reception level of thermal noise from other antenna elements.

  In other words, in this way, the passenger is seated in a normal posture on the seat to be detected without being affected by the thermal noise radiated from the passenger seated in a seat different from the seat to be detected. Whether or not the passenger is seated in a normal posture can be detected.

It is a block diagram showing the structure of the whole seating state detection apparatus of embodiment. It is explanatory drawing showing the arrangement | positioning state of the antenna element arrange | positioned around the seat used as detection object. It is a flowchart showing the seating state detection process performed with a seating state detection apparatus. It is explanatory drawing explaining the state by which the child seat was attached around the seat used as a detection target. It is explanatory drawing showing the state which provided the antenna element in the pillar of the motor vehicle.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing the overall configuration of the seating state detection device of the present embodiment.
The seating state detection device 20 of the present embodiment is provided for each seat of an automobile, and is based on the reception level of thermal noise by the five antenna elements 11 to 15 that receive millimeter-wave band thermal noise emitted from the occupant's body, When the occupant is seated in a normal posture, it is determined whether or not the occupant is seated in a normal posture that allows the airbag to be activated safely. Is constituted by a microcomputer centering on the CPU 22, ROM 24, RAM 26 and the like.

  Also, the seating state detection device 20 includes an input unit 28 that captures the received level of thermal noise from each of the antenna elements 11 to 15 by A / D conversion, a communication unit 30 connected to a communication line that constitutes the in-vehicle LAN, and a CPU 22. In addition, a bus line 32 for connecting these components including the ROM 24 and the RAM 26 is provided.

  The communication unit 30 is for communicating with various electronic devices such as the airbag control device 60, the engine control device 62, and the alarm device 64 mounted on the automobile via a communication line.

  As shown in the lower part of FIG. 1, the five antenna elements 11 to 15 include a receiving unit 16 for receiving millimeter-wave band thermal noise and an amplifying unit for amplifying a reception signal from the receiving unit 16, respectively. 17, a detection unit 18 that detects a reception signal amplified by the amplification unit 17 and generates a detection signal corresponding to the reception level, and an amplification unit 19 that further amplifies the output from the detection unit 18 The detection signal amplified by the amplifying unit 19 is input to the input unit 28.

  As shown in FIG. 2, among the five antenna elements 11 to 15, the antenna element 11 is provided at the upper position of the seat 2 to be detected on the ceiling 8 of the automobile. Then, the thermal noise of the millimeter wave band emitted from the passenger seated in the seat 2 is received.

Further, the remaining four antenna elements 12 to 15 are respectively provided on the door 9 located beside the seat 2.
The antenna element 13 is a millimeter wave band emitted from the chest or arm of the occupant when the occupant is seated on the seat 4 of the seat 2 and is leaning on the backrest 6 (that is, in a normal posture). The antenna element 15 is capable of receiving millimeter-wave band thermal noise emitted from the waist of the occupant when the occupant is seated in a normal posture on the seat 2. The antenna element 14 is disposed at a position where it can receive thermal noise in the millimeter wave band emitted from the occupant's foot when the occupant is seated in the seat 2 in a normal posture.

  The antenna element 12 receives millimeter-wave band thermal noise emitted from the chest of the occupant when the occupant is seated in the seat 2 but is not bent by the backrest 6 and is bent forward. It is placed in a possible position.

  Each of the antenna elements 11 to 15 is set to have a sharp directional characteristic so as to receive millimeter-wave band thermal noise emitted from a desired position of an occupant seated in the seat 2, and the directivity direction is As shown by the arrows in FIG. 2, it is set in a direction substantially orthogonal to the ceiling 8 or the wall surface of the door 9.

  2, (a) is a side view showing a state where the seat 2 to be detected is viewed from the side opposite to the door 9 provided with the antenna elements 12 to 15, and (b) It is the top view which looked at the seat 2 used as detection object from the ceiling 8 side.

Next, FIG. 3 is a flowchart showing a seating state detection process repeatedly executed at regular intervals by the CPU 22 of the seating state detection device 20.
As shown in FIG. 3, when this process is started, first, in S110 (S represents a step), the state of the ignition switch (IGSW) is acquired from the engine control device 62, and the current IGSW is in the on state. (That is, whether or not the automobile engine is currently in operation). Then, when the IGSW is off and the engine is stopped, the processing is finished as it is.

  On the other hand, if the IGSW is on and the engine is operating, the process proceeds to S120, and the detection signal (in other words, the millimeter wave band by the antenna element 11) is transmitted from the antenna element 11 provided on the ceiling 8 via the input unit 28. In step S130, it is determined whether or not the read detection signal (reception level) is a high level equal to or higher than a predetermined determination level.

  In S130, when it is determined that the detection signal (reception level) is at a high level, millimeter-wave band thermal noise radiated from the occupant is incident on the antenna element 11 (in other words, It is determined that an occupant is seated in the seat 2), and the process proceeds to S140.

  In S140, the detection signal (in other words, the reception level of the thermal noise in the millimeter wave band) is read from all the antenna elements 12 to 15 provided in the door 9 next to the seat 2 via the input unit 28, and then continues. In S150, based on the detection signals (reception levels) from the read antenna elements 12 to 15, the occupant sitting on the seat 2 sits in a normal posture leaning on the backrest 6 of the seat 2. It is determined whether or not.

  When it is determined in S150 that the occupant is seated in the seat 2 in a normal posture, the process proceeds to S160, and an airbag operation permission command is output to the airbag control device 60. Then, after the airbag control by the airbag control device 60 (specifically, the vehicle collision monitoring and the airbag inflating operation at the time of the vehicle collision) is started, the processing is temporarily ended.

  On the other hand, if it is determined in S130 that the detection signal (reception level) is a low level lower than the predetermined determination level (specifically, if it is determined that the passenger is not sitting in the seat 2), or in S150 When it is determined that the occupant is not seated in the seat 2 in a normal posture, the process proceeds to S170.

  In S170, the airbag control device 60 outputs an airbag operation inhibition command to stop execution of the airbag control by the airbag control device 60, and then the process is temporarily terminated.

  Note that the seating posture determination process executed in S150 is such that the detection signal (reception level) from the antenna element 12 is less than a predetermined determination level, and the detection signals (reception levels) from the other antenna elements 13 to 15 are received. When all of them are above the predetermined determination level, it is determined that the occupant is seated in a normal posture, and if any one of the antenna elements 12 to 15 has a detection signal (reception level) that deviates from this condition. The seating posture of the occupant is set to be determined as not normal.

  As described above, the seating state detection device 20 of the present embodiment includes the four antenna elements 12 to 15 provided on the door 9 disposed beside the seat 2 to be detected and the upper side of the seat 2. The five antenna elements consisting of the antenna elements 11 arranged in the are connected.

  In the seating state detection process executed as the seating posture determination means in the CPU 22 of the seating state detection device 20, first, a detection signal from the antenna element 11 disposed above the seat 2 (thermal noise in the millimeter wave band). Based on the reception level), it is determined whether or not an occupant is seated on the seat 2, and if it is determined that the occupant is seated on the seat 2, the detection signals (millimeter-wave band signals) from the other antenna elements 12 to 15 are determined. Whether or not the occupant is seated in a normal posture is determined based on the reception level of thermal noise.

  For this reason, according to the seating state detection device 20 of the present embodiment, a time-consuming determination process is performed in which the seat 2 to be detected is imaged with a camera and the captured image is image-processed as in the past. Therefore, it can be determined in a short time whether or not an occupant is seated in the seat 2 in a normal posture.

  Moreover, according to the seating state detection apparatus 20 of this embodiment, since it is not necessary to use the light source which irradiates the vicinity of a seat, or the camera for imaging a two-dimensional image, an apparatus structure can be simplified and manufacturing cost can be reduced.

  Further, according to the seating state detection device 20 of the present embodiment, when it is detected that an occupant is normally seated in the seat 2 to be detected, the airbag provided for the seat 2 can be operated. When an airbag operation permission command is output to the airbag control device 60 so that it is not possible to detect that the occupant is normally seated in the seat 2 to be detected (that is, no occupant is seated in the seat 2) If the posture is bad even when sitting, an airbag operation prohibition command is output to the airbag control device 60 to prohibit the inflation of the airbag.

  Therefore, according to the seating state detection device 20 of the present embodiment, when the occupant is not sitting on the seat 2 or when the posture is poor even when sitting, the airbag is prevented from inflating, and the airbag is not inflated. It is possible to prevent the safety from being lowered due to the necessary expansion.

  If it is determined in S150 that the seating posture of the occupant is not normal, the operation of the airbag is stopped because the posture of the occupant seated in the seat 2 is poor with respect to the alarm device 64. May be executed, and then the process may proceed to S170.

  Next, in the present embodiment, as an antenna element for detecting the sitting posture of the occupant, thermal noise radiated from the chest (or arm) that is the upper body of the occupant when the occupant is seated in the seat 2 in a normal posture. The antenna element 13 for receiving the antenna, the antenna elements 14 and 15 for receiving thermal noise radiated from the waist and legs, which are the lower body of the occupant, when the occupant is seated in a normal posture, and the occupant bends forward The antenna element 12 for receiving thermal noise radiated from the chest (or arm) of the occupant is provided, and the reception level of thermal noise by the antenna elements 13 to 15 is equal to or higher than a predetermined determination level. When the reception level of the thermal noise by the element 12 is less than a predetermined determination level, it is determined that the seating posture of the occupant is normal.

  For this reason, according to the seating state detection device 20 of the present embodiment, as shown in FIG. 4, when the child seat 70 is placed on the seat to be detected and the infant is sitting thereon, All (or part) of the reception levels of thermal noise by the antenna elements 13 to 15 are less than the determination level.

  Therefore, according to the present embodiment, when an infant or a child is sitting on the seat 2 via an auxiliary tool such as the child seat 70, it is erroneously detected that the occupant is seated in a normal posture, and the air The bag operation permission command is not output, and safety can be improved.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various aspect can be taken in the range which does not deviate from the summary of this invention.
For example, in the above embodiment, the vehicle door 9 is described as being provided with the four antenna elements 12 to 15 for posture determination. However, the antenna element for posture determination is seated in a normal posture on the seat 2. If it is possible to receive two systems of thermal noise radiated from the upper body and lower body of the occupant, it is possible to determine whether or not the occupant is seated in a normal posture based on the received level, so that the antenna element 13 and the antenna element 14 (or The seating posture of the occupant may be determined using the two antenna elements 15).

  Further, in this case, the antenna element for posture determination is not provided in the door 9 next to the seat 2 to be detected, but, for example, in a pillar 80 positioned obliquely forward of the seat 2 as shown in FIG. Two antenna elements 82 and 83 for posture determination are provided, and each antenna element 82 and 83 receives two systems of thermal noise radiated from the upper body (for example, the chest) and lower body (for example, the waist) of the occupant. May be.

  5A is a side view showing the seat 2 to be detected as viewed from the side opposite to the pillar 80 provided with the antenna elements 82 and 83, and FIG. It is the front view which looked at the seat 2 used as a candidate for detection from the front of vehicles.

Further, in order to increase the sitting posture determination accuracy, the number of antenna elements may be increased. Therefore, the number of antenna elements may be further increased as compared with the above embodiment.
On the other hand, the seating determination antenna element 11 provided on the ceiling 8 of the vehicle is not necessarily provided, and is provided at a place other than the ceiling 8 such as below the seating part 4 (or in the seating part 4). Also good.

  In the above-described embodiment, the antenna elements 11 to 15 are described as receiving millimeter-wave band thermal noise (in other words, radio waves) radiated from the occupant, but the received radio waves are in the microwave band. Also good.

  In the above embodiment, the sitting state detection device 20 has been described as being configured separately from an electronic control device (so-called ECU) such as the airbag control device 60, but the function as the sitting state detection device 20 is described. Is realized by an operation of a microcomputer constituting the ECU as one function of an electronic control device (ECU) mounted on the vehicle, such as an airbag control device 60 or an electronic control device for a keyless entry system. You may do it.

  DESCRIPTION OF SYMBOLS 2 ... Seat, 4 ... Seating part, 6 ... Backrest part, 8 ... Ceiling, 9 ... Door, 11-15, 82, 83 ... Antenna element, 16 ... Reception part, 17 ... Amplification part, 18 ... Detection part, 19 DESCRIPTION OF SYMBOLS ... Amplification part, 20 ... Seating state detection device, 22 ... CPU, 24 ... ROM, 26 ... RAM, 28 ... Input part, 30 ... Communication part, 60 ... Airbag control device, 62 ... Engine control device, 64 ... Alarm device , 70 ... Child seat, 80 ... Pillar.

Claims (2)

A vehicle occupant seating state detection device for detecting that an occupant is seated in a normal posture on a vehicle seat,
An occupant seated in the seated part of the seat and the upper body of the occupant who has been incorporated into the body part around the seat to be detected and is seated in a normal posture in the seat and drowned in the backrest of the seat A plurality of antenna elements each receiving thermal noise incident from a plurality of reception target positions, where the lower body is located;
A seating posture determination means for determining whether or not an occupant is seated in a normal posture on the seat from the reception level of thermal noise by the plurality of antenna elements;
A vehicle occupant seating state detection device comprising: One of the plurality of antenna elements is an occupant detection antenna element disposed below or above a target seat,
The seating posture determination means determines whether or not an occupant is seated in a target seat from the thermal noise reception level of the occupant detection antenna element, and determines that the occupant is seated in the seat. The vehicle occupant seating state detection device according to claim 1, wherein it is determined whether or not the occupant is seated in a normal posture based on a reception level of thermal noise from another antenna element.

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